Numerous training aids and golf club designs have been developed to help golfers develop and consistently replicate the ideal swing. Such training aids have generally been of three types; those that attempt to control the motion of the golfer's body; those that attempt to control the motion of the golf club; those that help golfers direct the club along an ideal path. The present invention fits into the later category. The first two categories will be reviewed first.
Meeker and Crouch, U.S. Pat. No. 4,815,743 disclose a large circular plate, termed a member, mounted on a support structure at an angle corresponding to the ideal swing plane. The golfer sticks his head through an opening in one edge of the plate and practices executing his golf swing without contacting the plate. Besides the size, expense and unwieldiness of this structure, it does little to control the actual movement of the golf club and does not specify how to determine the ideal swing plane.
Romano, U.S. Pat. No. 5,474,299 discloses a system of linkages and a rotor that connects to the golfer's hand and rotates as the golfer executes his or her swing. This large mechanism is complex and does not control the important link between the club grip and club head. Further, the disclosure does not specify how to align the rotor to the ideal swing plane. Numerous other inventions that attempt to control body motion fail to address the last, critical linkage in the complex system that starts at a golfer's feet and ends at the point where the club contacts the ball, the golf club itself. This is why so much attention has been devoted to the second category of training aids, those that attempt to control the golf club.
Harper, U.S. Pat. No. 5,538,251 discloses a rotation training structure that interconnects between a vertical support structure and the golf club that purports to guide the club through a perfect swing plane. However, the inherent flexibility in the large system of mechanical linkages prevents precise control of the swing plane, whether or not it is ideal.
Dayton, U.S. Pat. No. 6,645,084 B1 discloses a swing training device consisting of a large free-spinning wheel that attaches near the head of the golf club and makes
contact with the ground at the moment of contact with the ball. This system purports to help users improve timing and release of hands, but actually inhibits the type of ball striking that compresses the ball between the turf and club face that is universally recommended for irons. Further, the added weight of the system disrupts normal feel of the golf club. No training system that attempts to control the motion of the golf club works for all users. They all suffer from the disadvantages that the mechanisms, rather than the golfer, control the motion of the club and the golfer's experience with the system is different than the real-world without it. Shortcomings of these systems have led to the proliferation of training aids that attempt to influence the club to follow the ideal swing plane, rather than directly control the club's motion.
Novosel, U.S. Pat. No. 6,558,267 B2 discloses a hinged training club claimed to act substantially like a conventional golf club in every way, and whose hinge breaks when the user executes a flawed swing. An advantage of this club is that it can be used
both on the practice range and on a real golf course, but no real golfer wants to run the risk of the hinge breaking during a real golf swing, turning a bad swing into a catastrophic swing. Further, this system does not allow the golfer to practice with his or her own clubs.
Gauer, U.S. Pat. No. 6,945,875 B2 discloses a golf training device that includes a ball alignment marker and a template that identifies a preferred path of movement of the hand through a golf swing. The template also includes lines that identify the preferred orientations of the club face during the swing. The major shortcoming of this system and numerous similar systems is that they do not address the mechanics of actually making the club face follow the desired path and they do not account for the vertical motion of the club head through the ball and into the turf.
Numerous training aids have been invented that employ lasers that provide feedback on the orientation of the club shaft during the swing. For example, Freer, U.S. Pat. No. 4,913,441 discloses a laser swing training device that attaches to the butt of the golf club grip. The laser is intended to follow a path traced on a training mat on the ground, and in so doing help the golfer keep the club on an ideal swing The disadvantages of this and similar systems are that they can interfere with the golfer's hands and it is difficult to precisely align the laser with the golf shaft. Further, such systems direct the eyes of the golfer away from the ball during the golf swing. Variations on this system, including those disclosed by White and Burrus, U.S. Pat. No. 5,467,991, Pellegrini, U.S. Pat. No. 5,665,006, Lauffer and Parkinson, U.S. Pat. No. 5,954,592, and Marley, U.S. Pat. No. 6,059,668 all use similar approaches that suffer similar disadvantages.
Systems that influence the proper alignment of the golf club and its subsequent motion, while minimizing interference with the golfer, provide the greatest benefit to golfers. Lambert, U.S. Pat. No. 5,632,484 discloses a liquid-filled, transparent domed vial that attaches to the free-end of a golf club, and includes a bubble that indicates the angular alignment of the shaft. The problems with this system are that it is difficult to precise align the dome with the shaft to obtain accurate, consistent readings, and there is no unique position of the bubble in the dome that corresponds to the preferred shaft alignment to follow an ideal swing plane.
Spitzer, U.S. Pats. No. 6,468,166 B1 and No. 6,814,672 discloses systems that attach directly to the golf shaft, thereby eliminating the misalignment problem, that measure the lateral misalignment of the club face. The systems consist of alternate embodiments of curved bubble tubes, similar to the bubble tubes commonly found in carpenter level tools, but curved downward to keep the bubble at the top of the arc when the toe of the club is vertical. The major shortcoming of this system is that it does not provide the golfer with any new useful information and it ignores the more critical angle that the shaft makes with the ground. Golfers can readily perceive when the club face does not point toward the target. Further, Spitzer's inventions do not assure that the club face is square with the ball and pointing toward the target, but only that the toe of the club is vertical. Finally, the most critical shaft angle for starting and maintaining the club on the ideal swing plane is the angle that the shaft makes with the ground, which is not addressed by Spitzer's inventions.
Larson, U.S. Pat. No. 6,346,050 discloses a simple system for properly aligning the club shaft with the ground. The system includes a block bored with a plurality of holes that make different angles with the ground and a stake that the golfer can insert in the various holes. To use the system the golfer aligns the club shaft parallel to the shaft stuck in the block. The major problems with this system are that it relies on the user correctly judging when the two shafts are parallel, and it is not practical to use the system during actual play.
The unmet challenge is to devise a system that helps golfers properly align the golf shaft with the ground to start the club on the ideal swing plane, yet not disrupt normal use of the golf club.
Studies have shown that the best professional golf drivers create a 45-degree angle between the club shaft and the ground at ball impact. Ben Hogan, John Daly, and Tiger Woods all create a perfect 45-degree angle. Further, most professional golfers have a shaft angle of 45 to 47 degrees at impact while most amateurs have impact angles above 50 degrees. Such high shaft angles increase both ball spin and launch angle, leading to shorter drives and flight trajectories more susceptible to hooks and slices. Deviations from the 45 degree angle on the low side also have negative consequences. For example, professional golfers Fred Funk and Cory Pavin both have shaft angles close to 40 degrees at impact. Their drives tend to go straight, but short compared to other professional golfers. A device that helps golfers start their driver shafts on the ideal 45-degree swing angle, and helps maintain that plane angle throughout the swing would help both amateur and professional golfers. Such a device is the objective of the present invention.
The present invention is distinguished from prior art in that it directly measures the angle between the club shaft and ground, contains a built-in reference to the ideal club angle, and is small enough and sufficiently light weight to not affect the golf swing. Further, the device quickly clips onto and off the golf club, making it convenient to use during actual play.